In Japan, Nissan Motor introduced its new series-hybrid drive system called e-POWER along with its application in the Note. This marks the first availability of e-POWER technology for consumers, marking a milestone in the electrification strategy under Nissan Intelligent Mobility.

e-POWER borrows from the EV technology in the Nissan LEAF. Unlike the all-battery-electric powertrain of the LEAF, e-POWER adds a small gasoline engine to charge the high-output battery when necessary, eliminating the need for an external charger while offering the same high-output. Nissan says that although e-POWER uses a much smaller battery than the LEAF (1.5 kWh vs 30 kWh), it delivers the same driving experience as a full EV.

Compared to LEAF, the batteries are 1/20th the size and made to fit under the front seats without having to sacrifice interior space.

—Naoki Nakada

Differences between powertrains. Click to enlarge.

The e-POWER system features full electric-motor drive—the wheels are completely driven by the electric motor—the EM57 traction motor from the LEAF—which delivers a maximum 254 N·m from 0-3008 rpm. The power from a high-output battery is delivered to the e-POWER’s compact powertrain comprising a gasoline engine, power generator, inverter, and a motor.

The engine is the 1.2-liter, three-cylinder HR12DE. In general a three-cylinder engine tends to be louder and with more vibration than a four-cylinder engine. Nissan used an outer balancer to reduce vibration and noise, achieving quietness equivalent to that of a four-cylinder engine.

In conventional hybrid systems, a low-output electric motor is mated to a gasoline engine range extender to drive the wheels when the battery is low (or when traveling at high speeds). However, in the e-POWER system, the gasoline engine is not connected to the wheels; it simply charges the battery. Unlike a full EV, the power source originates from the engine and not just the battery.

e-POWER delivers massive torque almost instantly, which enhances drive response and results in smooth acceleration. Also, the system operates very quietly, much like a full EV. Because e-POWER relies on the engine much less frequently, its fuel efficiency is comparable to that of leading conventional hybrids, especially during around-the-town commutes.

Development History. Nissan is actively pursuing a zero-emission, zero-fatality world for driving through its EV program and autonomous drive technology. To make this vision a reality, Nissan is developing “Nissan Intelligent Mobility,” which anchors critical company decisions around how cars are powered, how cars are driven, and how cars integrate into society, all while staying focused on creating more enjoyable driving experiences.

In 2006, Nissan’s engineers were able to reduce the battery capacity to match its competitors’ hybrid vehicles while still delivering desirable EV qualities, such as quietness and efficient energy use. In addition, application of Nissan’s technologies, such as the integration of a power-generating engine, electric motor drive for compact car use, strengthening of the powertrain’s rigidity and improvements in NVH levels, became the foundation of e-POWER and its implementation in the compact-car segment.

Nissan is committed to developing electric-powered powertrains that use various fuels to cater to the different requirements of the world’s markets. e-POWER is but one example of that quest and will strengthen Nissan’s lineup of electric-powered powertrains. Nissan is also conducting research and development of the SOFC (Solid Oxide Fuel Cell) fuel-cell vehicle.

Comments

Another planet destroyer from Nissan. Nissan needs to focus on developing sustainable cars that are affordable. In other words, develop a fully self driving ultra durable BEV taxi services just like Tesla is doing with Model 3.

The point of conventional hybrid driven the wheel directly is energy loses going through electrical path. The Nissan way also means the generator must be bigger, because it must cope with full power of the ICE (~60 kW). From the price perspective Toyota HSD should be cheaper and more efficient, as it uses smaller electric motors and a simple planetary gear without any clutches for transfering "half" the power over mechanical path and "half" over electrical path.

The truth is sometimes inconvenient but without it we can’t make a better world for future generations. Every attempt to make gassers more efficient will prolong the time man will burn fossils and therefore increase the destructiveness of the resulting global warming extinction event.

So Nissan is being counterproductive here even though the engineers and managers who do it probably are under the illusion they are doing something good.

I watched the video and what struck me was when he said "you can have so much fun with electric cars". My thoughts were, well not if they are self driving. Maybe the next step is the ability to transfer human thoughts and impulses to the self driving software to allow humans to continue to enjoy the driving experience.

My understanding is the gas engine is not connected to the drive train so the engine is like a range extender with a smaller battery. The battery must have a high power capacity or maybe they figured a way to wire the generator output around the battery to deliver high current to the motor. In any case the price is very impressive.
My impression however is that much of the efficiency gains in technology like this results in consumers to afford bigger vehicles and I have some sympathy to Henrik's lament.

Car can be made self driven for 95% or even 99% of all situations, but that is not good enough. Over the weekend I was driving in Austria, there was a construction site and a note in German that goes something like "white lines are not valid, new lines are marked with cones".

What about heavy rain in the night, where lines are not visible, people tend to go by the instinct (and die), self driving car will simply say it's not possible to get to point B, period. Don't say that Tesla has super x-ray vision to se the white lines on wet black shiny tarmac in the middle of the night. All they got is radar which has to low resolution and cameras that are good only in good visibility.

Musk doesn't lie, it's just that self driving capability will be possible only in perfect conditions and only on the infrastructure (roads) that will allow it. We are very far away from completely driverless cars.

This is an ICE powered car. The battery provides supplemental power for acceleration and short term energy storage during braking and to store over production of Hp of engine for short duration. It less expensive because the vehicle minimizes lithium battery needs.

The drive train is electric. The proliferation of electric drive train will probably continue to increase it's market share. It is attractive since the cost is lower and the vehicle has most of the benefit of EV without the short range and plug in issues. The car doesn't attempt like the Volt to be a dual system. It's more like the heavy duty industry of truck, ship, and train have.

It looks like a very good car to me.
If it really gets 87mph(US) it will be spectacular as there are no range problems at all.
In the near future, you could add a few more KwH battery (and a plug) and charge it whenever.
Even if you stuck a 300w solar cell on the roof, you could get say 2kwH over a work day's charge, which would be enough to travel 6-7 miles.

And remember, the electricity that people charge the full EVs with will be mostly fossil (unless you live in France or Norway).

If so, that is on the wildly optimistic Japanese cycle, and real world will be nothing like that.

However, the article says:

'The engine is the 1.2-liter, three-cylinder HR12DE. In general a three-cylinder engine tends to be louder and with more vibration than a four-cylinder engine. Nissan used an outer balancer to reduce vibration and noise, achieving quietness equivalent to that of a four-cylinder engine.'

I've got a 1.2 litre three cylinder engine in my Peugeot 208, and it is just fine.

A different beat to a 4-cylinder, but that is about all.

No excess noise, and the engine in the Nissan will be running at pretty constant revs anyway, with acceleration taken care of by the battery for overtaking etc.

I should have added that I am hoping it will be pretty much equivalent in fuel economy to diesel, and if it is it will have done its job of providing great fuel economy and far lower emissions than diesel.

@dave, yes, MPG
As you say, you'd have to see what the real world mpg turns out to be.
It would be way better than a diesel because you* could add battery to cover your typical commute, and then not worry any more as it can go as far as you want on ICE.
+ it would be way cleaner than a diesel.
(*"you the manufacturer", not "you the consumer").
An 8KwH battery could allow say 25 miles driving / charge.
You could charge in work and at home at 3Kw easily and you never need to worry about mileage as you can always run on gas if you need to.
The advantage of this scheme is that you can size your battery for typical distance driven rather than maximum distance driven.

'What is it?
Three cylinder engines, so long an oddball configuration, seem soon to become the norm. Vauxhall, VW and Ford have them and we can now add Peugeot. And you’ll not need more than a minute in the Peugeot 208 1.2VTI to see why.

Here is a cracking little engine, as full of fizz at its redline as its four pot brethren are of protestation. It’s smooth, easy on the ear and capable of conferring performance quite beyond its apparently modest output.

What's it like?
And this is illusory only in part. Of course its infectious enthusiasm helps create the mere perception of speed, but its nature also means you’re egged on into actually using its power while the less smooth fours always tempt you to change up. But here’s the killer: the 1.2-litre three cylinder 208 is so much lighter than the 1.4-litre four, their power to weight ratios are a meaningless 3bhp/tonne apart. But while the 1.4 does 50.4mpg, the 1.2 does 62.7mpg.

Given the price advantage too, the case for three over four would already be unanswerable. But it doesn’t stop there: the three lightens the car by an astounding 95kg – almost 10 per cent of its entire weight - and every gramme of it off the front end. In a light car like this, the effect on handling is transformative. It has balance and poise unknown to other 208s, and steering of a different order.

http://www.autocar.co.uk/car-review/first-drives/peugeot-208-1.2-vti

The noise is fine too.

And another, less enthusiastic but still positive take:

' The big news for the 208 after its facelift was the engine under the bonnet of this review car – Peugeot’s 1.2 litre three-cylinder PureTech, boasting 108bhp and 159lb/ft of torque, and the promise of 65.7mpg and 99g/km.

Just like every other three-cylinder engine, the economy promises just don’t translate in to the real world, but the 208’s 3-pot does seem better on the juice in the real world than Ford’s 1.0 litre EcoBoost, and despite some lively driving over a week of playing we averaged 42.1mpg.

…you spend most of your time in a gear lower than you normally would to keep the engine in the sweet zone. But do that and the 208’s got a fizzy, responsive nature that is really quite fun.
But the 1.2 litre three-pot is a likeable engine, and although it’s a bit vocal when you push on it’s quite an appealing noise, and it really does feel lively.

I’m with Davemart on the 3-cyl configuration, but I would also add that NVH is far less of an issue in the series hybrid. The reason is that the engine doesn’t transmit torque through a geartrain connected to the structure of the car. Yes, there are compliant mounts and other measures that attempt to decouple the structureborne vibration from the engine/trans to the body, but you can only do so much. An engine /generator can be situated any way the designer wants, with more options for structural and acoustic isolation from the body.

And to reiterate the series hybrid is an affordable way to minimize the biggest challenge to ICE: the inefficiency and related emissions from part-throttle/idling operation.

BTW: I was at a trade show recently and saw a mockup for a series hybrid Zero Turn Mower. The architecture of the machine was remarkably similar: small battery to “absorb” peak demand, with traction motors and all accessories (in this case mower motors) decoupled from engine speed. The designer claimed a 30% smaller engine with equal performance to hydromechanical. Here is the video of their display (sorta long and no sound but you'll get the picture):

Yep, you can get poor implementations in any technology.
The attraction of 3-pot is that it is loads lighter, and friction losses are less.

The implementation in my Peugeot is lovely, and as Herman notes, can be further isolated and silenced in a hybrid configuration.

It sounds just fine to me in the one I have got though, including for motorway cruising where listening to the radio at just under 80 mph is just fine, although the car is smallish ( small in the US) and light, so sound insulation is not a priority.

BTW, I don't always like my cars, but this one is good, at least for my tastes.

Series hybrid traditionally isn't very efficient in straight motorway conditions because of the energy-conversion losses (mechanical to AC electric to DC to chemistry inside the battery, then chemistry in the battery to DC to AC and back to mechanical in the traction motor). If the engine output more-or-less matches demand then you can avoid at least some of the battery charge/discharge loss, but the others are still there. Whether all these losses balance the ability to stop the engine under more circumstances and only allow it to run under more efficient operating conditions ... is a crapshoot and will vary depending on circumstances.

All this is why a Prius operates with mostly mechanical drive from the engine at higher road speeds. And so does a Volt, and so do all the other hybrids. There's a reason they did it that way.

The Japanese test procedure is hopelessly optimistic. Circumstances that contain a lot of idling and very gentle acceleration and low speeds could very well offset all those energy-conversion losses by keeping the engine stopped more.

But take the same vehicle out in the real world of higher speeds and faster accelerations and (for most of us) less idling ... and it is likely to be less efficient under those conditions than even a conventional non-hybrid powertrain.

I am assuming this thing is a Series Plug-in. The Commoner is already fat-and-lazy or will quickly become fat-and-lazy after owning one of these things and the commoner will get tired of Plugging it in because they are fat-and-lazy.

Real-world mileage for the commoner will be in the High 20s/Low 30s mpg.

The commoner should be prohibited from purchasing a Series Hybrid and should be mandated by law to purchasing a Parallel configuration for this very reason.

Actually, this powertrain has NO plug-in at all. It is a hybrid vehicle ... not a plug-in hybrid.

And let's not be legislating or prohibiting specific technologies, please. Let them survive or wither out on their own merits. Maybe Nissan has figured something out that Toyota and Ford have not. If they have ... more power to them and I wish them success. If reality intervenes ... let the consequences flow forth; they will become apparent in due course.

Series hybrid has not historically been the optimal way to set up a powertrain - but there are specific circumstances where it could be. Those circumstances don't coincide with my own driving patterns (lots of suburban and motorway). That doesn't mean they won't coincide with someone else's (heavy stop and go).